Title: Understanding Autonomous Vehicle Safety

Removing the human driver from a road vehicle fundamentally changes the assurance argument approach needed for safety. We must start with a deeper inquiry into what we actually mean by acceptable safety. A simplistic "safer than human driver" positive risk balance approach must be augmented with additional considerations regarding risk transfer, negligent driving behavior, standards conformance, absence of unreasonable fine-grain risk, ethics, and equity concerns. Once we have a more robust understanding of what it means to be acceptably safe, we will find that current standards frameworks and accompanying definitions are likely to be inadequate to assure safety due implicit assumptions that are violated when the human driver is removed. We propose a new framework for relating risk to acceptable safety based on satisfying multiple stakeholder constraints rather than taking a risk optimization point of view. This broadens safety approaches in a way needed to deal with autonomous vehicles.